Covers are applied to surfaces for reasons which depend on the nature of these surfaces. Thus, in the case of a pond such as a swimming pool, the cover can avoid pollution by leaves or animals and provide savings on energy, water and reagents, and can or must ensure safety of people, in particular of children. In a desalination pond or other fluid treatment pond, a cover makes it possible to avoid the liquid dilution due to rain or excessive evaporation due to heat.
In the case of a sports field such as a dirt or grass outdoor tennis court, a cover makes it possible to protect it against bad weather, in particular intermittent rain. Moreover, a vehicle body is notably covered to ensure the stability of the load with respect to the drop in pressure caused by the movement of the vehicle and protect it against bad weather. Covers are also used as blinds for greenhouses, winter gardens or vehicle windows in order to avoid any internal overheating, and as solar protection for terrace awnings.
In all cases, the aim is generally to obtain an economical cover device that allows for easy, safe, reproducible and rapid covering and uncovering, requiring minimal human intervention and, above all, that has a life that is as long as possible. Many devices for covering a surface have been developed, ranging from the basic models to the most sophisticated. Among the latter, the moving drum devices can be cited.
In a moving drum cover device, the motorized drum is mounted on a longitudinal translation mechanism. The latter moves the drum over the surface to be covered which literally makes it possible to “lay” the cover on the surface, upon its deployment, by unwinding it simultaneously from the drum during its longitudinal movement, then lift it, upon its removal, by winding it simultaneously onto the drum. The cover therefore does not slip over the surface either upon its deployment or upon its removal. The cover device also comprises a system for fixing the cover at a first transverse end of the surface to be covered such that the translation and the rotation of the drum cause the unwinding or the winding of the cover on the surface to be covered. Examples of automatic devices of this type are disclosed, for example, in the following documents: WO2005/026473, FR2900951, DE2257231, FR2893651, FR2789425, FR2743502, EP1719858, and on the website www.kimbay.fr. Moreover, a completely manual variant of the drum mounted with longitudinal translation is illustrated in the documents WO2007/036625 and U.S. Pat. No. 4,195,370.
In the present application, the terms “longitudinal”, “transverse”, and their derivatives, refer respectively to the direction of movement of the drum and to the direction of the axis of revolution thereof.
The moving drum cover devices illustrated above provide only a fixing of a transverse edge of the cover at a transverse end of the surface to be covered, the opposite edge remaining secured to the drum. No system for fixing the longitudinal edges of the cover is provided. In particular, in the case of a swimming pool, people moving onto the cover would not be retained by its longitudinal edges and could thus be plunged into the water. Furthermore, the lack of sealing of the cover on its longitudinal edges can promote the ingress into the swimming pool of dirt, dead leaves and twigs, as well as small animals such as mice or snakes. More sophisticated devices have been proposed that make it possible to reversibly fix the longitudinal edges of the cover upon its deployment, as in the document FR2803769 which provides a system for fixing the longitudinal edges of the cover consisting of grid sections that are raised then folded back section by section on said longitudinal edges of the cover by keeping these edges inside a gutter as the latter is unwound. In this design, the longitudinal edges of the cover are gripped without being locked, which provides lesser security, particularly in the case of swimming pools.
Another advantageous system that makes it possible simultaneously to fix the longitudinal edges of the cover upon its deployment and exert a transverse pulling force thereon to tighten it perfectly has been disclosed in WO2010/010152 and in WO2010/054960. In these devices, the longitudinal edges of the cover are provided with a cord or sealing bead which is introduced into the upwardly oriented opening of a rail in the form of a “U” section profile member, with one or two fins partially closing said opening. The sealing bead which slips under a fin and is retained in this position by suitable fixing means makes it possible to securely fix the longitudinal edges of the cover.
Even in the moving drum devices comprising means for fixing the longitudinal edges, at most three of the four edges of the cover can offer a relatively tight contact with the surface forming the perimeter of the surface to be covered: the two longitudinal edges, and the first transverse edge of the cover which is fixed to a first end of a surface to be covered. The second transverse end, the one where the drum is parked, cannot be sealed because it is simply laid on the surface of said lateral edge, falling from the drum. A current of air or of wind slipping under the drum can open a space between the second lateral end of the surface and the cover, thus allowing contamination of the surface despite it being covered. For example, in the case of swimming pools, this can be reflected in a contamination by leaves, twigs, grit, and even animals, potentially being introduced into the pond, despite the presence of the cover.
Also, a protective casing can be added, mounted on a carriage supporting the drum. Said casing is open on its face facing toward the surface to be covered forming a skirt defining a cavity containing the carriage and the drum. The casing comprises a rim defining the perimeter of its open face. Such a carriage has a function that is primarily esthetic, because it conceals the longitudinal translation mechanism of the carriage and the drum. Above all it serves a protective function for said translation mechanism and the drum. In the case of a swimming pool, the casing can also serve as a bench when it is parked at one or other of the transverse ends of the pool. It is clear that such a casing makes it possible to reduce the penetration of the wind under the cover, when the latter is deployed. However, in order to allow the movement of the carriage, the rim of the casing must at all points be located over obstacles located over the entire width of the surface upon the movement in the longitudinal direction of the carriage. For this reason, it is essential to leave a minimum space, dm, between the rim of the casing and a plane defining the outline of the surface, such that the space, dm, is greater than the height, ho, relative to said plane of any obstacle located in the path of the carriage and of its casing. Such obstacles can be a protruding sun deck, pebbles, reinforcing profiles, etc. This space, dm, between the rim of the casing and the plane defining the edge of the surface does not therefore make it possible to satisfactorily seal the last side of the surface.
The risk of lifting of the cover can be minimized by fixing a batten of metal or other material with high density, extending in the transverse direction of the cover, at a position corresponding to the second end of the surface to be covered. The weight of the batten makes it more difficult for wind or an animal to open a space between the edge of the surface and the cover. This solution is not however optimal because, on the one hand, in strong winds, the weight of the batten becomes insufficient to maintain the contact of the cover with the lateral edge of the surface and, on the other hand, the batten adds thickness to the drum when the cover is wound.
There therefore remains a problem in sealing the four sides of a surface covered by a cover deployed by a moving drum system. The present invention proposes a particular protective casing, making it possible to seal the two transverse sides of the surface when a cover is deployed.